WISEA J045921.21+154059.2: A Bright, Nearby Infrared Dwarf

Are you up for an observing challenge? If you have a telescope equipped with a CCD camera and an infrared filter, you might be able to detect the brightest known L-type infrared dwarf star WISEA J045921.21+154059.2. (This author prefers to use the term “infrared dwarf” rather than the more popular caconym brown dwarf.)

WISEA J045921.21+154059.2, also known as WISE J045921.20+154059.4 and 2MASS J04592088+1541054, is a high-proper-motion star located not far from Aldebaran in the constellation Taurus at α2000 = 4h 59m 20.89s, δ2000 = +15° 41′ 05.42″. This cool star has a spectral classification of sdL0. Though its parallax has not yet been measured, its high proper motion may indicate it’s a star just a few light years away. The “sd” classification on the L0 spectral type indicates that it is a subdwarf star—underluminous in comparison with a “normal” L0 star.

Infrared dwarfs—as their name implies—radiate mostly in the infrared portion of the spectrum rather than at visible wavelengths. You can see this in the apparent magnitudes listed below. Remember, the lower the number the brighter the star is at that wavelength/passband.